The video, which was shown to the news service but not released, reportedly was found by the nongovernmental organization Nuba Reports, which exposes bombings and other attacks on southern Sudan people by the military.
Ryan Boyette, 31, an American who is married to a Sudanese health worker and lives in the South Kordofan region of Sudan, where many of the attacks have taken place, provided the video to the news service.
In May, he posted an account of an attack on his village by Sudanese planes, including a bomb that fell some 50 yards from his home.
Boyette told AP that the cellphone video was found on the body of a dead Sudanese soldier and is believed to have been filmed by the dead man.
The cellphone video shows soldiers from a unit nicknamed the Match Battalion, an apparent reference to the burnings the force carried out, the news agency reported.
According to the news service, the five-minute video shows a soldier with a torch and then flames burning through the village of Umbartumbo in South Kordofan last summer, about two months after fighting erupted in the region in June 2011.
According to Nuba Reports, the fighting began weeks before South Sudan's independence last July. Sudan accuses South Sudan of arming and funding Sudanese Peoples Liberation Army-North rebels in the Nuba Mountains. The militia is allied with the rebels who fought a 22-year war that led to South Sudan's independence from Sudan.
According to AP, the video shows gray smoke hanging over the village and a commander ordering soldiers to burn the homes.
"Matches, where are the matches? Burn this house," the commander says, according to translation provided by Boyette, AP reported.
Amnesty International released a report last week saying South Kordofan and Blue Nile states in Sudan are bearing the brunt of fighting between Sudanese forces and the SPLA-N rebels. Many residents in those states supported the SPLA during the civil war for southern independence, but found themselves in Sudan after South Sudan's secession.
The report, based on interviews with refugees, said 144,000 people had fled to South Sudan and Ethiopia since last June because of indiscriminate bombings by the Sudanese air force and by a hunger crisis in the region.
According to Amnesty International, the bombings killed civilians and destroyed schools, churches and clinics. Hundreds of perceived supporters of the SPLA-N has been arrested, according to the report.
Since South Sudan gained independence, relations between the new nation and Sudan have been strained by disputes over oil revenues, oil transit fees and the border.
Peace talks between the two countries broke off last week with little progress. The United Nations has threatened sanctions if the two sides do not come to an agreement.
— Robyn Dixon
Photo: Refugees coming from the Nuba Mountains in Sudan's South Kordofan region wait to register with U.N. relief agents in South Sudan late last month. Credit: Giulio Petrocco / Agence France-Presse / Getty Images.